Sound for the Mikado, Improving on the Factory Speaker

The good news is that the Mikado comes with a speaker "free". The bad news is that it is the same typical stock speaker from Aristo

It is an 8 ohm, 1 watt speaker. It sounds remarkably good considering what it is. I think Aristo did one hell of a job making this speaker sound pretty good. It is a really cheap speaker.

But, it does not have much bass, even with the large enclosure in the tender.

The picture below is of the stock speaker. Notice the small circuit board overlaps the speaker. Also notice that there are 4 posts around the speaker, probably intended for a sound board over the speaker. You will have to relocate this small board, you can do this by drilling another hole in the board, in the nearest left hand corner, which will move the board away from the speaker. (Typically you will want to rewire the tender anyway, see how the stock wiring has one leg of each polyswitch (orange squares) completely unsupported? Just asking for vibration and motion to fracture the other end.

Well, I thought I could do better. I measured this speaker, it's a 70mm speaker, and the outer diameter is 3". (It is NOT a 3" speaker, speakers are measured by the dimension of the outer edge of the surround, the flexible suspension that holds the cone).

Below is pictured the replacement speaker I used, it's from Litchfield station, you can see the model number on the tag in red printing below, SP-78-SHP-08. Notice the surround is nice flexible foam, not just the typical cardboard that is part of the main cone. This allows greater flexibility and greater excursion. This should mean more power carrying capability, more bass and less distortion when producing bass:

How about this side view? Which would you pick? I guess it's obvious this is a no-brainer.

The new speaker has 4 mounting holes in the metal surround. A quick trip to a disc sander and sand it down to be the same outer diameter of the original speaker. This will remove the mounting tabs and make the speaker circular.

The speaker fits in here, and can use the original 4 clamps. I also cut out all the vertical grillwork with a dremel, but left the horizontal piping you see through it. A bit of work, but the stock grill blocks too much sound.

I used a carbide bit to cut off the thick grill, but not cut the piping below, took about an hour of hobbying, but I believe it gives better sound. The reflective surface of the original grill should theoretically cause more distortion, and obviously there is less restriction to the soune. Anyway, I think it sounds better now. I have not sprayed it black yet, so you can see the difference: (you don't really need to spray it if you don't mess up any of the paint on the outside/bottom)

The result is very good without adding any other enclosure.